Grits reminds us that not all forensic science is scientific.
I ran across an interesting article documenting critiques of forensic dentistry. In it, bite mark expert Dr. Gregory Golden:
concedes that there’s little scientific research to back claims from forensic odontologists in court — but he hopes to see that change. “What we’re trying to do,” he says, “is to develop proper, unbiased research techniques that take into consideration real-time mechanisms or setups for researching bite marks.”The problem, he says, is that it’s difficult to conduct realistic studies on how bite marks injure living human flesh. In the past, studies have been conducted on cadavers and anesthetized pigs, with dental models mounted in vice grips. But such studies don’t accurately reflect bites on living human flesh, and Golden adds that “it’s almost impossible to find voluntary subjects offering themselves to be bitten severely enough to be wounded.”In the meantime, though, he wants to keep drawing his expert witness fees until the science either justifies or debunks his premises. While it’s understandable that few subjects would be willing to be seriously bitten in service to science, that’s not a good excuse for courts to admit unreliable evidence.
[…]
Unfortunately, as the National Academy of Sciences articulated in a 2009 report, many forensic disciplines aren’t really “science” at all and forensic odontology is one of them. Instead, like tool mark or hair-and-fiber analyses, the method of identification involves subjective comparison, not scientific proof.
Like many people, I suspect, I have gotten most of my information about criminal justice from pop culture – movies, TV shows, mystery and detective books. Needless to say, this provides a distorted view about how things really work. Part of the problem is that writers and fans love all that forensics stuff. Flashy technology, futuristic techniques, genius investigators – we eat it all up. Putting aside all the dramatic license and CSI-style distortion of timelines, excitement levels, and just plain frequency of usefulness, the fact remains that we’re no better at distinguishing the things that have solid scientific basis from those that turn out to be junk. And when we come across stuff like that in one of our favorite shows or books, it’s not like a correction gets issued later, or that we’d hear about it if one did. So people come to believe in these things, people who subsequently serve on juries. I’ve read about the problems with fingerprint analysis for years, and I still have more belief in in than doubt. It’s going to take a long time and a lot of updated information to clear things up.